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Brown bullhead

Onglets

Description

Distinguishing features

The brown bullhead is a member of the catfish family. It has a thick, rounded body, heavier toward the front. The back of its head and its body and sides are yellowish brown to olive, or even grey to dark blue. It has small eyes and 4 pairs of barbels around its mouth. Its tail is square and slightly forked and there is an adipose, rayless fin on its back in front of its tail. There are sharp, sawtoothed spines at the base of its dorsal and pectoral fins; the first spine can be locked in an erect position. Its sides are sometimes mottled with dark splotches. Its belly is cream coloured. It has no scales, but its skin has many taste glands. It has several rows of fine, sharp teeth.

Reproduction

Brown bullheads spawn in the daytime, in May and June, once the water temperature reaches 21.1 degrees Celsius. The male or female or even both of them make a nest, which is simply a hole in the muddy or sandy bottom. After a few mutual caresses with their barbels, the male and female position themselves head to tail, side by side, for fertilization. The female lays from 2,000 to 13,000 cream-coloured eggs (3 mm), covered with a sticky viscous mucous. Both parents care for the nest, even fanning the eggs and stirring them up with their fins and barbels to oxygenate them. The eggs hatch after 6 to 9 days. The young are initially yellow, but turn black the next day and are protected by their parents for several weeks. They form a spherical school of 600 to 800 young fish. When they reach 5 cm, the young leave the school and live on their own. They grow relatively quickly and reach sexual maturity at three years.

Diet

Brown bullheads feed mainly at night, near or on the bottom, using their barbels to find their prey. They are omnivorous, meaning that they eat a bit of everything. The young feed on various insect larvae and other tiny organisms. Adults feed on debris, molluscs, insects, leeches, crayfish, worms, frogs, algae, plants, small fish and even fish eggs.

Predators

Pike, muskellunge, walleye and many other fish feed on brown bullheads when they are young and swimming in large schools. As they grow, the fry develop fine-toothed spines on their dorsal and pectoral fins, making them less appealing as prey. Adults can lock these spines in the erect position as protection from predators. Even so, a muskellunge was caught in the wild with a healed scar on its side where a catfish spine had protruded, showing that these spines are not foolproof protection. Humans are also major predators of brown bullheads.

Habitat

Brown bullheads live on the bottom in shallow, weedy, muddy areas with warm water. Although they are found throughout North America, in Quebec they occur only in the southern part of the province, below an imaginary line between Ottawa and Quebec City. The largest populations are found west of Trois-Rivières and in the Eastern Townships. They live in ponds, small lakes and bays and at the bottom of slow-moving streams and rivers.

Ecology, behaviour

They tolerate warm water of 26 to 28 degrees Celsius, and even up to 37 degrees. They adapt well to lower oxygen levels and even to polluted environments. Under adverse conditions, they protect themselves by burying themselves completely in the mud. In highly polluted waters they may be the only fish species present! Their flesh, varying from reddish to pink, is edible and can be quite tasty. In fact, brown bullheads are reared commercially on fish farms in the southern United States. Because they live on muddy bottoms where visibility is limited, they use their barbels to smell and taste their surroundings and find prey, which they then eat with their hundreds of small sharp teeth. Brown bullheads are an invasive species, since they are highly resistant to pollution, warmer water and lack of oxygen, giving them an unfair advantage when they compete with other fish for territory.

French name

Barbotte brune

Scientific name

Ameiurus nebulosus

Phylum

Chordata

Class

Actinopterygii

Order

Siluriformes

Family

Ictaluridae

Size

20 to 35 cm long in Quebec (55 cm or more in Florida)

Weight

0.5 kg on average, but up to 3.6 kg in Ontario

Life span

6 to 8 years

Status

Abundant in its habitat

At the Biodôme

There are brown bullheads in the porcupine pond in the Laurentian Maple Forest ecosystem. Of all the dark shapes roaming the bottom of the pond, those with small barbels are brown bullheads. The fish meal we feed them sinks to the bottom and slowly softens. We also feed them shrimp. They can also eat insects and different animal and plant debris that accidentally falls into the water and sinks to the bottom.